Answer : 72,000
Ex: Let x be his monthly salary.
The equation to set up would be
7920=0.11x
This equation represents 11% of monthly salary = 7920
To solve you divide 0.11x by 0.11 to get x by itself. then you do what you do to one side to the other. therefore you divide 7920 by 0.11 and you get 72,000